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(11) | EP 0 454 071 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Wavelength conversion by quasi phase matching and the manufacture and use of optical articles therefor |
| (57) Articles and process for wavelength conversion are disclosed which use a series of
aligned sections of optical materials for wavelength conversion selected from materials
having the formula K1-xRbxTiOMO₄ where x is from 0 to 1 and M is selected from P and As and materials of said
formula wherein the cations of said formula have been partially replaced by at least
one of Rb⁺, Tl⁺ and Cs⁺, and at least one of Ba⁺⁺, Sr⁺⁺ and Ca⁺⁺. The series of sections
is characterized with regard to a change in nonlinear optical coefficient, section
length, and section Δk (i.e. the difference between the sum of the propagation constants
for the incident waves and the sum of the propagation constants for the waves generated).
The sections are selected such that the sum for the series of the product of the length
of each section with the Δk is equal to about 2πN (where N is an integer other than
zero) and the nonlinear optical coefficient for at least one section is changed relative
to the nonlinear optical coefficient for at least one adjacent section. Also disclosed
is a process for preparing a channel waveguide for wavelength conversion systems wherein
areas along a portion of a crystal substrate surface used for forming the desired
channel are alternately masked and unmasked during cation replacement by immersion
in a molten salt. |